2 files changed, 81 insertions, 29 deletions

diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 07cb2172bd09..bd66bd28a43f 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -716,9 +716,11 @@ static int thermal_get_trend(struct thermal_zone_device *thermal,
 	if (thermal_get_trip_type(thermal, trip, &type))
 		return -EINVAL;
 
-	/* Only PASSIVE trip points need TREND */
-	if (type != THERMAL_TRIP_PASSIVE)
-		return -EINVAL;
+	if (type == THERMAL_TRIP_ACTIVE) {
+		/* aggressive active cooling */
+		*trend = THERMAL_TREND_RAISING;
+		return 0;
+	}
 
 	/*
 	 * tz->temperature has already been updated by generic thermal layer,
diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index 0cf3dce55462..735e6e6daada 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -1076,6 +1076,81 @@ void thermal_cooling_device_unregister(struct
 }
 EXPORT_SYMBOL(thermal_cooling_device_unregister);
 
+/*
+ * Cooling algorithm for active trip points
+ *
+ * 1. if the temperature is higher than a trip point,
+ *    a. if the trend is THERMAL_TREND_RAISING, use higher cooling
+ *       state for this trip point
+ *    b. if the trend is THERMAL_TREND_DROPPING, use lower cooling
+ *       state for this trip point
+ *
+ * 2. if the temperature is lower than a trip point, use lower
+ *    cooling state for this trip point
+ *
+ * Note that this behaves the same as the previous passive cooling
+ * algorithm.
+ */
+
+static void thermal_zone_trip_update(struct thermal_zone_device *tz,
+				     int trip, long temp)
+{
+	struct thermal_cooling_device_instance *instance;
+	struct thermal_cooling_device *cdev = NULL;
+	unsigned long cur_state, max_state;
+	long trip_temp;
+	enum thermal_trend trend;
+
+	tz->ops->get_trip_temp(tz, trip, &trip_temp);
+
+	if (!tz->ops->get_trend || tz->ops->get_trend(tz, trip, &trend)) {
+		/*
+		 * compare the current temperature and previous temperature
+		 * to get the thermal trend, if no special requirement
+		 */
+		if (tz->temperature > tz->last_temperature)
+			trend = THERMAL_TREND_RAISING;
+		else if (tz->temperature < tz->last_temperature)
+			trend = THERMAL_TREND_DROPPING;
+		else
+			trend = THERMAL_TREND_STABLE;
+	}
+
+	if (temp >= trip_temp) {
+		list_for_each_entry(instance, &tz->cooling_devices, node) {
+			if (instance->trip != trip)
+				continue;
+
+			cdev = instance->cdev;
+
+			cdev->ops->get_cur_state(cdev, &cur_state);
+			cdev->ops->get_max_state(cdev, &max_state);
+
+			if (trend == THERMAL_TREND_RAISING) {
+				cur_state = cur_state < instance->upper ?
+					    (cur_state + 1) : instance->upper;
+			} else if (trend == THERMAL_TREND_DROPPING) {
+				cur_state = cur_state > instance->lower ?
+				    (cur_state - 1) : instance->lower;
+			}
+			cdev->ops->set_cur_state(cdev, cur_state);
+		}
+	} else {	/* below trip */
+		list_for_each_entry(instance, &tz->cooling_devices, node) {
+			if (instance->trip != trip)
+				continue;
+
+			cdev = instance->cdev;
+			cdev->ops->get_cur_state(cdev, &cur_state);
+
+			cur_state = cur_state > instance->lower ?
+				    (cur_state - 1) : instance->lower;
+			cdev->ops->set_cur_state(cdev, cur_state);
+		}
+	}
+
+	return;
+}
 /**
  * thermal_zone_device_update - force an update of a thermal zone's state
  * @ttz:	the thermal zone to update
@@ -1086,9 +1161,6 @@ void thermal_zone_device_update(struct thermal_zone_device *tz)
 	int count, ret = 0;
 	long temp, trip_temp;
 	enum thermal_trip_type trip_type;
-	struct thermal_cooling_device_instance *instance;
-	struct thermal_cooling_device *cdev;
-	unsigned long cur_state, max_state;
 
 	mutex_lock(&tz->lock);
 
@@ -1124,29 +1196,7 @@ void thermal_zone_device_update(struct thermal_zone_device *tz)
 					tz->ops->notify(tz, count, trip_type);
 			break;
 		case THERMAL_TRIP_ACTIVE:
-			list_for_each_entry(instance, &tz->cooling_devices,
-					    node) {
-				if (instance->trip != count)
-					continue;
-
-				cdev = instance->cdev;
-
-				cdev->ops->get_cur_state(cdev, &cur_state);
-				cdev->ops->get_max_state(cdev, &max_state);
-
-				if (temp >= trip_temp)
-					cur_state =
-						cur_state < instance->upper ?
-						(cur_state + 1) :
-						instance->upper;
-				else
-					cur_state =
-						cur_state > instance->lower ?
-						(cur_state - 1) :
-						instance->lower;
-
-				cdev->ops->set_cur_state(cdev, cur_state);
-			}
+			thermal_zone_trip_update(tz, count, temp);
 			break;
 		case THERMAL_TRIP_PASSIVE:
 			if (temp >= trip_temp || tz->passive)